A botanist discovers a plant that lacks the ability to form starch grains in root cells, yet the roots still grow downward. This evidence refutes the long-standing hypothesis that _____
A) falling statoliths trigger gravitropism
B) starch accumulation triggers the negative phototropic response of roots
C) starch grains block the acid growth response in roots
D) starch is converted to auxin, which causes the downward bending in roots
E) starch and downward movement are necessary for thigmotropism
Answer: A
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Speciation in snails can be said to be instantaneous because left-handed and right-handed snails cannot mate and coiling direction is:
a. caused by a single gene. b. affected by ploidy. c. affected by chromosomal translocations. d. caused by multiple genes.
____ are good examples of consumers
a. Omnivores b. Detritivores c. Herbivores d. Carnivores. e. All of the above.
Which of the following prevent uncontrolled cell division?
a. Proto-oncogenes b. Tumor suppressor genes c. Gene mutations d. Negative regulators
Most invasive species have a far greater impact in their new home than they did in the community in which they evolved. Why is this?
What will be an ideal response?